Re: [PATCH] pci/switchtec: fix stream_open.cocci warnings (fwd)

From: Bjorn Helgaas
Date: Wed Apr 17 2019 - 17:54:26 EST


On Sat, Apr 13, 2019 at 06:50:57PM +0200, Julia Lawall wrote:
> Hello,
>
> Kirill will explain about this issue.
>
> julia
>
> ---------- Forwarded message ----------
> Date: Sat, 13 Apr 2019 11:22:51 +0800
> From: kbuild test robot <lkp@xxxxxxxxx>
> To: kbuild@xxxxxx
> Cc: Julia Lawall <julia.lawall@xxxxxxx>
> Subject: [PATCH] pci/switchtec: fix stream_open.cocci warnings
>
> CC: kbuild-all@xxxxxx
> TO: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> CC: Kurt Schwemmer <kurt.schwemmer@xxxxxxxxxxxxx>
> CC: Logan Gunthorpe <logang@xxxxxxxxxxxx>
> CC: Bjorn Helgaas <helgaas@xxxxxxxxxx>
> CC: linux-pci@xxxxxxxxxxxxxxx
> CC: linux-kernel@xxxxxxxxxxxxxxx
>
> From: kbuild test robot <lkp@xxxxxxxxx>
>
> drivers/pci/switch/switchtec.c:395:1-17: ERROR: switchtec_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
>
> Generated by: scripts/coccinelle/api/stream_open.cocci
>
> Fixes: 8a29a3bae2a2 ("pci/switchtec: Don't use completion's wait queue")
> Signed-off-by: kbuild test robot <lkp@xxxxxxxxx>

Based on Kirill's subsequent email saying this is already queued to
the merge window, I assume I need to do nothing here.

I think a signed-off-by from a robot, i.e., not from a real person, is
meaningless, and I don't think I would personally accept it. It's
certainly OK to indicate that a patch was auto-generated, but I think
a real person still needs to take responsibility for it.

Documentation/process/submitting-patches.rst says it must contain a
real name (no pseudonyms or anonymous contributions), and I don't
think a robot fits in the spirit of that.

I see that
https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/commit/?id=8a29a3bae2a2
(mentioned below) does have a good signed-off-by from Sebastian, but
that's not *this* patch, so I don't know what's what.

Bjorn

> ---
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-5.0.y-rt-rebase
> head: 794c294ae4483c240429c25a0d18e272e92c94de
> commit: 8a29a3bae2a2dfb0116cd8791d9700515d6e765e [154/311] pci/switchtec: Don't use completion's wait queue
> :::::: branch date: 7 hours ago
> :::::: commit date: 7 hours ago
>
> Please take the patch only if it's a positive warning. Thanks!
>
> switchtec.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/drivers/pci/switch/switchtec.c
> +++ b/drivers/pci/switch/switchtec.c
> @@ -392,7 +392,7 @@ static int switchtec_dev_open(struct ino
> return PTR_ERR(stuser);
>
> filp->private_data = stuser;
> - nonseekable_open(inode, filp);
> + stream_open(inode, filp);
>
> dev_dbg(&stdev->dev, "%s: %p\n", __func__, stuser);
>